A straight woman who desires to watch lesbians perform sexual acts is referred to as bi-nosy. Bi-nosy is distinct from bi-curiousity as a bi-nosy woman doesn't actually want to dabble in woman-on-woman lovemaking, but prefers to watch.
Lesbian 1: Your roommate was standing in the doorway watching us make love last night. Maybe she's bi-curious. We should ask her to join us one of these days for a three-way session of scissoring.
Lesbian 2: Nah, she's LDS and straight as an arrow. Just another bi-nosy bitch.